Spool valves



June 13, 1967 A. BEECH 3,324,885

SPOOL VALVES Filed Oct. 26, 1964 4 Sheets$heet 1 A.-S. BEECH- SPOOL VALVES June 13, 1967 Filed on. 26, 1.964

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A. S. BEECH SPOOL VALVES June 13, 196 7 4 Sheets-Sheet J?- F'iled Oct. 26, 1964 [MW W v I Filed Oct. 26, 1964 June 13, 1967 A. s. BEECH 3,324,885

SPOOL VALVES 4 Sheets-Sheet 4 I l g I 5: I I

i, I 1% Q 77 A5 7 United States Patent 3,324,885 SPOOL VALVES Austin Sidney Beech, Leighton Buzzard, England, assignor to Austin S. Beech & Company Limited, Leighton Buzzard, England, a British company Filed Oct. 26, 1964, Ser. No. 406,465 Claims priority, application Great Britain, Nov. 4, 1963, 43,474/ 63 8 Claims. (Cl. 137624.18)

This invention relates to spool valves of the kind comprising a spool, a ported sleeve having a bore in which the spool works and a valve body fitted to the sleeve, in which body there are fluid passages connected to the ports in the sleeve, and means for operating the spool. Various ditficulties arise in the manufacture of valves of this kind, partly owing to the fact that normally the valve body is subject to fluid pressure and must be free of porosity and completely pressure-tight. Another difliculty lies in the provision of the ports in the liner, which normally have to connect the bore in which the spool works with the exterior of the liner and involve the drilling of radial passages through the liner. If these are to be of adequate area to provide for high rates of fluid flow a considerable number of radial holes must be drilled, which weakens the liner, occupies a large amount of time in manufacture and generally demands great accuracy in the placing of the holes. Moreover, if a port consists of a circumferential row of holes the initial shape of the port openings when the spool passes the holes is bounded by a short circular segment of the hole which is crossed by the edge of the spool to form a chord to the circle and the chord is initially a very short one so that the valve opening is not sudden as is desirable and the stroke of the spool has to be correspondingly longer. Increase of the stroke of the spool involves a wider spacing of the ports, and a greater length of valve body for a given port opening.

It is an object of the present invention to overcome these disadvantages.

According to the present invention, a valve of the type above referred to is characterised by the fact that the ports in the sleeve are formed by internal circumferential grooves and the sleeve is cut away at one side to afford a joint face, the joint face intersecting the grooves which form the ports, and by the fact that part of the valve body containing the fluid passages is provided with a joint face on to which the fluid passages open and which is jointed to the joint face of the sleeve, so that access of pressure fluid from the passages to the exterior of the remainder of the liner is prevented. Preferably the part of the valve body to which the sleeve is jointed is a separate member from a part which houses the sleeve.

The effect of this construction is that the main part of the valve body, other than that in which the fluid passages are cut, is not itself subjected to fluid pressure and may 'be manufacured of a casting or of other material which is not suitable for resisting heavy fluid pressures, whether hydraulic or pneumatic. Another advantage is that as the ports are cut all the way round the interior of the liner in the form of circumferential grooves, the stroke of the spool for a given valve opening is reduced and the overall dimensions of the valve can be reduced correspondingly. A further advantage is that the labour of drilling accurately large numbers of holes is elimi nated.

According to a further feature of the invention a valve body is provided having a ported joint face or faces to which two or several different sleeves as above described may be jointed and the passages in the valve body are made to serve both or all the sleeves.

The means for operating the valve spools in the vari- 3,324,885 Patented June 13, 1&6?

ous sleeves may be any desired. For example if a plurality of spools are arranged parallel to one another these spools may be operated mechanically in predetermined order by a cam shaft. Alternatively the spools may be operated by solenoids or by hand levers or by hydraulic or pneumatic pistons. With a construction of this kind it is possible for the ported portion of the valve body to which the spool sleeves are jointed to be a part of a larger mechanism such as a machine tool and the sleeves can be applied to suitable faces on the outside of the valvebody portion of the machine tool. This is particularly convenient where a number of spools are required to control parts of a machine tool because the ported sleeves can be removed separately for servicing without disturbing the pipework on the tool itself.

In some cases there may be no complete housing for the sleeve but the sleeve may be clamped to the valve body by clamping screws or a clamping plate or saddle and it is quite a simple matter to connect actuating means, for example a solenoid-housing or housings, to the end or ends of the sleeve by means of external tie rods.

It will be appreciated in this connection that as the part of the valve body which houses the spool is not itself subjected to fluid pressure it is immaterial whether this part of the valve body is a complete housing or is merely a sufiicient construction for keeping the sleeve clamped against the joint face.

The following is a description, by way of example, of one construction in accordance with the invention.

In the accompanying drawings:

FIGURE 1 is a plan of a valve;

FIGURE 2 is a vertical section upon the line 22 of FIGURE 1, looking in the direction of the arrows;

FIGURE 3 is a side elevation of the construction shown in FIGURE 1;

FIGURE 4 is a perspective view of a liner;

FIGURE 5 is a detail of a tappet;

FIGURE 6 is a perspective view of a gasket plate;

FIGURE 7 is a view similar to FIGURE 2 of a modified construction;

FIGURE 8 is a similar view of a further modification;

FIGURE 9 is a section through a cam operated construction in accordance with the invention, taken upon the line 9-9 of FIGURE 10, and

FIGURE '10 is a front elevation of the construction shown in FIGURE 9 with parts broken away to show the interior.

The valve shown in FIGURES 1 to 3 comprises a body 11 containing a cylindrical liner 12 of hardened steel the interior of which is honed or grooved to form a close-working fit for a valve spool 13, also of hardened steel. The liner 12, instead of being of hardened steel may in some cases be of hard cast iron or anodised aluminium. In manufacture, the liner is first bored (as shown at 20, FIGURE 4) and turned (in the soft state if of hardenable steel) and five circumferential grooves 14, 15, 16 are turned in the interior of the bore at the positions corresponding to the ports, which in the case described, consist of a central supply port 16, two distribution ports 15 (one on each side of the supply port) which may be connected say, to the two ends of a hydraulic or penumatic cylinder and outside these exhaust ports 14, one towards each end of the liner. The liner 12 is made of a suflicient external diameter to enable the ports to be provided without reducing the thickness of metal between the outer periphery of the groove for each port and the outside of the liner to a point where it is thinner than is requisite for strength. Outside the ports 14 at each end of the liner, there is a recess 17 to receive a sealing ring 18 of rubber or nylon or the like.

While the liner 12 is still in a soft state a flat 19 is milled across it from side to side at such a distance from the centre of the liner that the internal bore 20 is not interfered with but the external peripheries of the grooves 14, 15, 16 which form the ports, are cut into, making five port-openings, 21, 22, 23 in the side of the liner. It will be understood that if the liner is cast, a fiat may be cast on it beforehand if desired. The ends of the liner do not share in this fiat but are left circular to support the sealing rings 18. In this state the liner is if necessary hardened, ground and honed. If of cast iron it may be ground and if necessary lapped, or if of aluminium, after grinding or otherwise bringing it to exact size, it is anodised.

The liner 12 is fitted into the valve body 11 which has a bore to fit the exterior of the liner and an intermediate fiat at 24 FIGURE 3 corresponding to the flat joint face 19 which has been provided on the liner itself. Against this flat valve body there is placed a valve base 25 which contains distribution passages 26, 27, 28 corresponding to the five ports 14-16 inthe liner. The passages have fiat-sided ports of the same dimensions and spacings as the openings 21, 22, 23 in the side of i the liner 12 and the ports in the base 25 are in such a location that they coincide on assembly with the ports in the liner.

Between the base and the fiat joint face on the valve body 24 and the liner there is inserted a gasket plate 30 consisting of a stout piece of sheet steel pierced with elongated port openings corresponding to the ports in the base and the liner but somewhat larger. Joint rings 31, initially of circular shape and made of rubber or nylon or the like are provided, the perimeter of which is equal to the perimeter of the port openings in the gasket plate 30 and these joint rings are inserted in the gasket plate and are thereby deformed into an elongated shape similar to that of the apertures in the gasket plate as shown in FIGURE 6. The thickness of the gasket plate 30 is such that it is a little thinner than the thickness of the joint rings 31 and the flat 19 on the liner is such that when the liner is in position in the valve body 11 it is slightly under flush relatively to the joint face on the valve body. The base is held to the valve body by four screws 33 and when the screws are tightened up the force of the screws is wholly taken between the valve body 11 and the base 25, no direct pressure being exerted between the base 25 and the joint face 19 on the liner, but the joint rings 31 in the gasket plate engage both the base and the joint face of the liner 12 and seal the joint. Thus the liner is not deformed by the pull of the screws and a fluid-tight joint is secured which prevents a leakage of pressure to the exterior of the liner 12 and to the joint between the back of the liner and the bore in the valve body in which the liner fits. Thus also, the valve body 11 which holds the liner is not itself subjected to fluid pressure.

At each end of the valve body there is secured in place by appropriate screws a solenoid winding (not shown) and an iron magnet 36 in a case 34, which is held against the valve body by a base plate 35 to which the solenoid magnetic circuit 36 is secured.

At the left-l1and end of the liner 12, as viewed in FIGURE 2, outside the sealing ring 17 is a spacer ring 37 beyond which. is a grooved disc 38 supporting a second sealing ring 39. These parts are held in place by a circlip 40 which fits into a groove in the interior of the bore in the valve body 11 which receives the liner 12. The movable solenoid core (which is not shown in the drawing) is intended to operate against a tappet 41 which passes through a sealing ring in the centre of the disc 38 and has a head 42 to bear on the end of the spool 13. Thus, if the solenoid in the casing 34 at the left-hand end of the valve body is energized, the spool will be pushed by the tappet 41 to the right, as veiwed in the figure.

At the right-hand end of the liner 12 there is another tappet 43 which enters the solenoid at that end and will be pushed to the left if that solenoid is energised. At this end there is a grooved disc 48, similar to the disc 38 and having a sealing ring 49 around its periphery and a sealing ring 46 around the tappet 43. There is a spacer ring 47 similar to the ring 37, but thinner, and between this and the disc 48 is a disc 45 which is drilled diametrically to receive centralising balls 50 urged inwards by springs 51. These balls Operate on grooves 52, 53, on the stern of the tappet 43 and serve to determine which of two operative positions the spool 13 occupies. In one position, as shown, pressure is admitted from passage 28 through port 16 to port 15 and thence to distribution passage 27, the left-hand exhaust port 14 and passage 26 being cut off. The right-hand distribution passage 27 is open to exhaust passage 26. In the other position, the spool 13 is moved to the left till groove 53 is engaged by the balls 50 and then the distribution port 15 is closed to the supply passage 28 and the left-hand exhaust port 14 and passage 26 are open to the distribution passage 27. In this position of the valve, pressure has access to the right-hand distribution port 15 and the right-hand exhaust port 14 and passage 26 are closed. There is no effective intermediate position. A double-acting cylinder and piston device connected at its opposite ends to the distribution ports 27 will therefore, according to which of the solenoids in the casings 34 is energised, be moved to one end or the other of its stroke.

The top of the valve body 11 has a junction box 55 formed in it, with a cover 56 and passages 57, 58 to the interior of the casings 34, throngh which the solenoid connections can be led. Each of the tappets 41 and 43 is formed at its end as shown in FIGURE 5, with a head 61. The end of the tappet rod (41 as drawn) is reduced a little and passed through a hole in the head 61 and is rivetted in place by stamping it with cross-grooves 62, 63. The spool 13 has a hole 63 drilled through it from end to end and the grooves prevent the tappet making a tight joint on the end of the spool. When the spool is moved. therefore, air can pass freely fro-m the chamber 67 inside the ring 37 to the chamber 66 inside the ring 47 and the valve is not made sluggish in operation, as would be the case if there were no provision for freedom of air passage through it.

FIGURE 7 shows a modification in which, instead of one of the solenoids, there is, at the left-hand end of the valve as viewed in the figure, an end plate 64 which supports an axial spring 65. The right-hand end of the valve is like the left-hand end of FIGURE 2 and there are no centering springs. This valve will cause a piston and cylinder motor connected to the distribution passages 27 to move in one direction or the other, according as the solenoid is energised or de-energised.

In FIGURE 8 there is shown another modification, using two solenoids and tappets similar to 41, FIGURE 2, and discs 38 at both ends. Between the discs 38 and the valve-sleeve 12, instead of spacer rings such as 37, there are centralising springs 70, which bear on collars 71. The collars 71 are shaped so that they receive the heads 61 of the tappets 41 in recesses in their inner faces. The effect is that, if neither solenoid is energised, the spool 13 is centralised as shown and the distribution ports 27 are cut off both from supply 28 and exhaust 26. Thus a motor connected to ports 27 will be held in whatever position it may have reached if current is cut off from both solenoids, and it will be moved to one end or the other of its stroke if current is supplied to one or the other of them.

Referring to FIGURES 9 and 10, these show a construction in which there is a valve body 75 corresponding to the base 25 of FIGURES 1 and 2 but formed as part of the body of a machine tool the remainder of which does not appear in the figure. As in FIGURES 1 and 2, ports 26, 27 and 28 are provided in the body 75 but in this case there are three sets of such ports, the second and third set being numbered in the figure 126 to 128 and 226 to 228, respectively. The three ported portions of the valve .body have faces against which bear three gaskets 30 (FIGURE 9) corresponding to the gasket 3-0 of FIGURE 2, and against each gasket there is clamped a liner 12 which is held in a valve housing 76 corresponding to the housing 11 of FIGURES 1 and 2. The housing 76 is provided with three bores to receive the three liners 12. The lower ends of these bores are closed by plugs 77 and the undersides of the plugs are held in place by a plate 78 secured to the housing 76 by screws, as shown. In each of the liners 12 there operates a valve spool 80 which is similar to the spool 13 of FIGURE 2 but is urged upwardly by a spring 81 in the plug 77 beneath it and has at its upper end a tappet 82 similar to the tappet 41 of FIGURE 5, which passes through a spacer 83 and a sealing disc 84 held in place by a circlip 85. All these parts are provided with appropriate sealing rings as shown. At the upper part of the valve body 76 there are three lugs 86 on which are pivoted rockers 87 which bear on the tappets 82 and carry cam rollers 88. Above the cam rollers 88 is a cam shaft 90 supported in bearing brackets 91 and carrying cams 92, 93, 94 which operate the cam rollers of the three rockers 87. Thus, each of the valve spools 80 is operated in turn by the cam shaft 90 and the supply of pressure to the various ports is determined as to its duration and the order of operation of the parts to which the ports are connected by the relative shape of the cams. The cam shaft 90 may be driven by any desired operating gear, for example by a ratchet mechanism which is energised a step at a time, by limit switches or the like on the machine tool.

The order and timing of operation of a number of difierent valves and of the parts which they control is therefore very simply provided for and if the parts within the housing 76 require to be serviced they can all be removed without interfering with the supply connections or the cam shaft. The housing 76 is held in place by setscrews 95 which pass into the valve body 75 between the various sets of ports.

'In all these embodiments of the valve, the stroke of the valve spool 13 is short and the valve body is compact for the reasons already described. One result is that the solenoids have short strokes and are for this reason more efilcient. Moreover, the reduced size of the parts reduces the amount of machining, there are no radial holes to be drilled in the liner, the flow of fluid through the valves is more streamlined than when radial holes are provided as ports and the total work required for machining purposes is less.

Moreover, the base 25, the gasket plate 30, the liner 12 and the spool 13 can readily be made of non-corrosive material if corrosive fluids are to be employed, without alfecting the manufacture of the valve body 11 or the solenoids 34.

I claim:

1. A valve comprising a valve housing having a generally cylindrical bore, a valve seat comprising a generally cylindrical liner sealingly mounted in said bore, said liner having a plurality of axially spaced internal annular grooves, said liner being cut away at one side to alford a generally planar face intersecting said grooves to form ports through said liner communicating with said grooves, said valve housing being cut away to expose said planar face, a base having a planar face, gasket means, means connecting the base to the valve housing sealingly holding the gasket between the planar face of the liner and that of the base, ports in the base registering through ports in the gasket with the liner ports, and valve means carried by the liner for communicating selected annular grooves.

2. A valve as claimed in claim 1 in which the valve means comprise a spool and in which the valve housing carries an electrical operating solenoid for the spool.

3. A valve as claimed in claim 2 in which the solenoid operates the spool through a sealed tappet and in which the spool has a longitudinal internal passageway extending from end to end whereby air may freely pass through the spool when the spool is operated by the tappet.

4. A valve as claimed in claim 3 in which the said tappet has a head which is grooved to prevent it from sealing the said passageway.

5. A valve as claimed in claim 1 in which the said ports in the gasket contain sealing rings.

6. A valve as claimed in claim 5 in which the sealing rings stand proud of the gasket before the said valve base is connected to the said valve housing whereby the sealing rings are laterally compressed during said connection.

7. A valve as claimed in claim 1 in which the base has a planar face and associated ports for the jointing of a multiplicity of separate valve housings to said face and in which the said ports are connected to only one set of fluid passages within the base, which passages thereby serve all the valve housings.

8. A valve housing as claimed in claim 7 in which the 'base to which the valve housings are jointed forms part of a larger machine and in which the liners and spools within the valve housings are arranged parallel to one another and are operated mechanically in predetermined order by a cam shaft.

References Cited UNITED STATES PATENTS 2,879,788 3/1959 Beckett 251-367 X 2,910,089 10/1959 Yarber 137-62565 3,060,970 10/1962 Asian 137625.69 3,200,847 8/1965 Gillmore 137-625.69 X 3,215,158 11/1965 Bass 137-62569 X ALAN COHAN, Primary Examiner. 

1. A VALVE COMPRISING A VALVE HOUSING HAVING A GENERALLY CYLINDRICAL BORE, A VALVE SEAT COMPRISING A GENERALLY CYLINDRICAL LINER SEALINGLY MOUNTED IN SAID BORE, SAID LINER HAVING A PLURALITY OF AXIALLY SPACED INTERNAL ANNULAR GROOVES, SAID LINER BEING CUT AWAY AT ONE SIDE TO AFFORD A GENERALLY PLANAR FACE INTERSECTING SAID GROOVES TO FORM PORTS THROUGH SAID LINER COMMUNICATING WITH SAID GROOVES, SAID VALVE HOUSING BEING CUT AWAY TO EXPOSE SAID PLANAR FACE, A BASE HAVING A PLANAR FACE, GASKET MEANS, MEANS CONNECTING THE BASE TO THE VALVE HOUSING SEALINGLY HOLDING THE GASKET BETWEEN THE PLANAR FACE OF THE LINER AND THAT OF THE BASE, PORTS IN THE BASE REGISTERING THROUGH PORTS IN THE GASKET WITH THE LINER PORTS, AND VALVE MEANS CARRIED BY THE LINER FOR COMMUNICATING SELECTED ANNULAR GROOVES. 